Infestation by unwanted, nonindigenous vegetation is a common problem. Infestations can become so severe that native ecosystems are destroyed. For example spartina, commonly known as cord grass, is threatening to disrupt and/or destroy saltwater ecosystems in the Pacific Northwest. Another example similar to spartina, is purple loosestrife which infests freshwater lakes, rivers and wetlands.
Typically, spartina infests a tide flat by forming one or more colonies of dense vegetation. The dense vegetation traps fine sediment creating an elevated high marsh. Invading colonies of spartina grow together, further expanding the marsh. These marshes block water access and displace native shellfish, salt marsh plants, migratory birds, fish and other wildlife. In addition, the marshes can build to a level sufficient to block outflow of tidal water. Such blockage can result in increased flooding in shoreline areas, especially during periods of above-normal tides or heavy rains.
Eradication of invading spartina colonies has been difficult because the vegetation can grow from either seeds or root pieces, the root pieces also being known as rhizomes. When attempts are made to pull or dig up clumps of spartina, significant parts of the root mass usually break off, leaving rhizomes for future regeneration. Present eradication methods involve cutting the spartina with high speed rotary cutters, a process that disperses the cut weed and actually enhances the spread of the spartina, hand pulling and chemical application, all of which are quite ineffectual or undesirable.
Accordingly, the present invention provides an improved solution to the removal and eradication of unwanted vegetation in general, and more particularly to the eradication of unwanted vegetation along shorelines, such as spartina and purple loosestrife.